The course is an introduction to the history of twentieth century architecture from 1900 to present. It will explore the implications of different conceptions of the twentieth century architectural history as an ongoing discussion about the appropriate architecture for the modern period. Also, this course will introduce the social, economic and environmental factors that influence and shape architecture. In the previous era, canons were used to identify the paradigms of excellence, but not easy in the twentieth century as they proved short-lived. In addition, it was an era of development and growth of new materials, technologies, and dominant economic systems.